yo JUiUriin Xo. 28. 



throat, I. Yellow Warbler, i. Cedarbirds, a large flock of not less than 

 100, Mourning Dove, i, with nest on ground in hay-field. Bobolink, 

 2, with nest on roadway. Total, 134. All within the village limits but 

 not including anywhere near the number of species ol)served on that 

 day, little time on the whole being given to birds. 



These lists give without a doubt a tolerably fair estimate of our local 

 ornis during the period of reproduction or early summer months — that 

 is, in a rough way, for as is well known quite a number of forms not 

 given here are known to nest within our limits. Indeed, the village 

 of Glen Ellyn proper could furnish a half dozen such additional species 

 and which easily could be augmented by special trips in quest of them 

 to the neighboring parts of the township. 



Such notable examples for instance are the Pied-billed Grebe, Least 

 Bittern, Virginia and Sora Rails, Spotted Sandpiper, and possibly Kill- 

 deer, Hairy Woodpecker, Phoebe, Green-crested Flycatcher, Least Fly- 

 catcher, Chipping Sparrow, Yellow-throated Vireo, Redstart, House 

 Wren, White-breasted Nuthatch and Chickadee. 



The grand total of the number of units or individuals actually heard 

 or seen on these several trips is 1245, and from which it is thought 

 allowable to make the following deductions. But for our. purposes of 

 calculation we will call it in round numbers 1200. Of the thirty-six 

 sections the county contains, fifteen of these were visited, my path not 

 being doubled excepting in the last three trips where corresponding 

 allowances were made. It is figured that my field of observation would 

 naturally cover at least four acres at each notation, or twenty to each 

 section ; or, in other words, one-eighth of each section was gone over by 

 these observations. 



If twelve hundred individuals were the sum total in covering one- 

 eighth of the territory represented by fifteen sections, a completed esti- 

 mate of the entire field, based on the above calculations, would there- 

 fore yield 9600 individuals, or one-fifteenth of that, 640 to each section, 

 which in my opinion is not only a low estimate, of the number of birds 

 that should possibly be recorded, but is fifty per cent, less than should 

 really exist there, for the reason that my notes are confined almost en- 

 tirely to the seeing or hearing of male birds alone, therefore the females 

 and young are not taken into consideration thus far. Multiplying the 

 640 by 2 we have 1280 adult birds for each section, and 36 times this the 

 magnificent showing of 46,080 for the entire township, or 414,720 for the 

 whole county, which is made up of nine townships. 



Yet this is not all ; for, as has been said, these estimates affect only the 



